Pyrometer



June 5, 1928. 1,672,229

R. C. PAIRMAN PYROMETER Filed Sept. 3, 1925 1.. hllllll dumm..

HIMMIIN www INVENTOR.

Patented June 5, 1928.

PATENT formel-3'.

ROBERT" C. :PAIRM'AIL 0F OAKLAND, aCAIaIEOfBNIfA.

-m'zRQMErn-m.

Application 'med september :ninas A,serialm.54,as`2.

Thisinvention relates to afpy'rometer andV especially that type in whichithe co-emc'ient of expansion of two metals is 'employed ,to

actuate'the temperature indicator.

HThedpyrometerformingjthe sbjjectniatter o'fthefpresent application consists `of ay substantially noneexpanding element in (the `form of -a tube which is adapted to Abe "exposed to hot 44gases or another medium, the n temperature which itl is desired 'to Ydetermine. This tube contains an `expansible element'in the form-of arod :andthe objectfoi the invention is.to permit free expansionr or contraction of `the vrod `with changesottemperature without -danger of binding or in any manner stressingv either element,` {topprovide means whereby the expanding action of` the.rod maybe transmitted to moveatemperature ind'icating Iarm orpointer over a graduated scale7 to provide astructurewhich is exceedingly simple and Arugged 4and ,in which lost motion and vwe ar'is automatically taken y up 'by gravity and spring Caction, to provide means whereby 'lost motion, Wear, etc., maybe readily compensatedffoigfmd further to provide a structure which-*maybe easily taken apart for inspection, 5repair", cleaning, etc. p

One form which lmy invention may assume is eXempliied inthetollo'wing description Iand lillustrated in ythe :accompanying drawings, in which- ,'Fig. l is asideelevationjof thepyrometer partially'insection. n

Fig. `2 is a cross section on line 2 2, F3011.

aeferring to `ai@ drawings in 'detail andy particularly to Fig. -l,it Willfbe noted thegpyrome'ter consists ofa tube A Whichiijs adapted to be exposed ito theho'tgasesor another medium Q the temperature of j which it is 'desiredto determine. lThe,tulbefis'pr'ovided with a head member 2 jthe exterior surface of whicheisitaperedjas at, 3 tjo"foim a fairly tight tjoint with ,relation `to .a sea't member 4. vThe opposite end of fthe tube g is provided withwa Screw plug' 5 whichfforms closure for 'the lower end Land which also serves the function of permittingremoval ,of

an-endfro'd generallyfindicated atB. 'This rod is constructed? fan cxp'nsilblelmteril such as brass` orfthe like, while the tbe, Ails preferably constructed of ,a :substantially nonee'xpan'sible metal such 'as invar `metal or l i lyimounte'dzas 'at`7 on'theplate isaprimary adua'tingglever 8. Inter'pcsed between vthe rodjB andthelever 8 isanintermediaterod 9. The jlower end of this/rod restsbygravity ontop ofthe expanding rod JB and the upper end .0f the intermediate rodis pivotally connected to the'lever 8 as at' 10. Formed in a plate ."6 near one edge `thereof is avv-slot 1l. 'Disposed on the rear iside of the plate is anadjustablebracket 12 "(see particularly Fig, l Thisbracketis slotted as indicated atii'andtapair of clamping screwsli pass through the slotted bracket and enter the plate '6. The ljbracket is ,provided with a head member 1'5 onits upper end andthisis engagedby an adjusting screw 16 which is carried'byailugl on the rear sideof the plated 'The'bracket'plate `l2 carries aupin 18 which n.projects Ythrough 'the' slot 111 in p'1at`ej6 and thlsl pin serves asia pivotalsupport for a pointer or indicator y*arm 19- which is (actuated by the primary lever 8 y through means ofjalink, 20,.this link being pivotal'ly attached to the respective levers has indicated at 2l and 22. lThe-,outer edgeof theplate is graduated 'as shownat, 23 'to indicatetemperature readings land the cpointer 19 moves eter Lis in actual operation.

`orthehfpurpose,of illustrating one of the usest`o which theI pyrometer may be x putthe elbow TC ywhich forms a connection between theheadfand the vexhaust,manifold of 'an i11- ternalcombustion motoigjifor instance ,a'Diesel mo'torgisillustrated. 'This'elbow is 4pro*- vided kvs'fiththe seat 4 forthe reception of the head Nportion off Vthe Apyrolleter and if ,it is desired'tlo determine the temperature of the exhaustgases before they enter kthe mani- Q'ld,jit'isIelelynecessary tooinsert the pyro'nieter as Vshown jin 'Figli The heated gases will rapidlyraise thetemperatureof thetexterior eXpaI'IdiDgtube/Ato thatof the gases. 'This Willfin lturntby radiatiomand combustion heat the rod B interior thereof, which -will freely i expand. [Its llength Qwill accordingly be increased in ,proportion to the ,temperature and the movement Uofexpanfsion be transmitted Vto the ,intermediate rod 9 thru theprirnary actuatinglever 8 las the intermediate rod is pivotally connected to the operating lever at a point closely adjacent the lever pivot 7 The opposite end of the lever will move upwadly and this movement is transmitted through the link 20 to move the pointer 19 over the graduated scale 23. In actual practice, the average temperature of the exhaust gases should range somewhere ,around 600 F. and if the proper amount of fuel is being fed to the engine and the exhaust valves are tight, the pointer will assume a position where it indicates 600 temperature. If, for any reason, too much fuel is being fed to the cylinders, the exhaust valves are leaking, or the fuel fed is too much retarded, it is immediately indicated by the pointer 19 as thel pointer will show higher temperature; for instance, 700 or 800, or whatever the case may be. This reading is immediately a warning to the operator who will then investigate to determine the cause thereof.

A pyrometer of this character is accordingly well adapted for use in connection with Diesel motors and the like as no delicate adjustments or construction is required. The tube A may be heavy and substantial to prevent warping and bending, and so may the expanding rod B. Thisv is also true of the intermediate rod and the levers 8 and 19 actuated thereby. Wear will, however, take place at the pivotal connections such as shown at 7, 10, 18, 2l, and 22, and such wear creates loose position and play. This must be compensated for, and it is for this reasonV that an adjustable support is provided for the pointer or lever 19. The bracket 12 is vertically adjustable on the rear side of the plate and may be moved in a downward direction by loosening the screw 111 andl tightening up onthe `adjusting screw 16. This forces the pivot 18 in a downward direction and will thus compensate for any wear that may have taken place. Loose position `is taken up by the weight of the lever and also by the spring indicated lat 30, this spring being secured to the lower end of the plate and thev outer end of the lever '8. This spring is of further importance as it permits the pyrometer to be placed in any position desired, whether it be vertical, horizontal, on an angle, or otherwise.

The upper end of the tube A is open, and dust, grease, or other foreign particles might thus enter between the tube and therod B- and cause sticking of the same. This is obviated in the present instance by placing a collar 31 on the intermediate rod. This serves as a cover for the opening and prevents foreign particles from dropping in or otherwise entering. Under extreme temperature conditions, it has been found that the brass rod B has a slight tendency to scale. Such scales when formed will cause the rod to stick, and it is therefore necessary to permit ready removal for the purpose of cleaning o the scales. This is accomplished by removing the pyrometer as a whole and unscrewing the plug 5, whichl permits the rod 8 to be taken out and cleaned by means of apiece of sandpaper, emery cloth, or the like, and similarly permits smoothing off of the interior surface of the tube. Considerable play may be permitted between the' rod and the tube, and this is also important at it obviates sticking and stressing of either of the elements; towit, the tube A and the rod B, when inoperation.

While certainv features of the present invention are more or less specifically illus-A trated, I wish it understood that various substantially non-expandible metal, Aa plug forming a closure for one end of the tube, the opposite end of the tube being open, a rod insertible in the tube and resting on the plug, said rod being constructed of an expansible metal and being freely expandible within the tube, a plunger member insertible in the openl end of the tube and resting on the lexpandible rod, said plunger member having a collar formed thereon and disposed below the open end of the tube to form a cover therefor to prevent admission of dust, a flat substantially triangular plate supported by the tube and having agraduated scale thereon, an indicator arm pivotally mounted on the yplate and movable with relation to the graduated scale on the plate, and means for transmitting movement from the plunger to said indicator arm.

2. A device of the character described comprising an elongated tube constructed of a substantially non-expandible metal; a plug forming a closure for one end of the tube, the opposite end of the tube being open, a rod insertible in the tube and resting on the plug, said rod bein constructed of an eX- pansible metal and eing freely expandible within the tube, a plunger member insertible in the open end of the tube and resting on the expandible rod, said plunger member having a collar formed thereon and disposed below the open end of the tube to form a cover therefor to prevent admission of dust, a flat substantially triangular plate supported by the upper end of the tube and having a graduated scale thereon, an indicator arm pivotally mounted on the late and movable with relation to the gra uated scale on the plate, a horizontally disposed lever pivotally mounted on one face of the plate, an in- 5 -dicating arm normally disposed and substantially parallel therewith and also pivotally attached to the plate, a pivotal coninner end of the indicating arm, and a spring attached to the outer end of the first-named lever and to the plate.

ROBERT C. PAIRMAN. 

